/*
 *******************************************************************************
 *
 * Copyright (c) 2016-2017 Advanced Micro Devices, Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/

#pragma once

#include "palMutex.h"
#include "palBuddyAllocator.h"
#include "core/platform.h"

namespace Pal
{
class Platform;

// =====================================================================================================================
// SvmMgr provides a clean interface between PAL and the BuddyAllocator, which is used to allocate and free GPU
// virtual address space for SVM allocations on Windows WDDM2 platforms. This GPU virtual address is shared with CPU.
// On WDDM1 platforms, VamMgr provides VA managements for SVM.
// On Linux platforms, SVM is not implemented yet. This class is intended to be used in Linux.
//
// Some commonly used abbreviations throughout the implementation of this class:
//     - VA:  Virtual address
//     - SVM: Shared Virtual Memory
class SvmMgr
{
public:
    explicit SvmMgr(Device* pDevice);
    virtual ~SvmMgr();

    Result Init();
    Result Cleanup();

    Result AllocVa(gpusize size, uint32 align, gpusize* pVirtualAddress);
    void   FreeVa(gpusize virtualAddress);

    gpusize GetStartAddr() const { return m_vaStart; }

private:
    Device*const m_pDevice;
    gpusize      m_vaStart;
    gpusize      m_vaSize;

    Util::BuddyAllocator<Pal::Platform>* m_pBuddyAllocator;  // Buddy allocator used for the suballocation

    Util::Mutex  m_allocFreeVaLock;                          // Mutex protecting allocation and free of SVM va

    PAL_DISALLOW_DEFAULT_CTOR(SvmMgr);
    PAL_DISALLOW_COPY_AND_ASSIGN(SvmMgr);
};

} // Pal
